'94 Chevy 1500

Update your progress on your various car projects.

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TheRookie
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Post by TheRookie »

We need to get together so I can get the brake controller swapped from my SS to your truck before the lease is up. Not a go fast part, but certainly a go truck part.
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TireSmoker
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Post by TireSmoker »

TheRookie wrote:We need to get together so I can get the brake controller swapped from my SS to your truck before the lease is up. Not a go fast part, but certainly a go truck part.
Is that something we can do?

-Dave
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TheRookie
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Post by TheRookie »

I've always had it done up at DLMR, that trailer place on 322 near 44. I'd be glad to just pay him to do it right. Not sure if you need an adapter, etc.
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Post by TireSmoker »

Basement Paul wrote: As CamaroBob once told me, "the most common carburetor problem, is a bad ignition system". Replace carburetor with FI, but the point is the same.

-BP
The corollary to that is "90% of ignition problems are a bad carb/tbi/mixture"

Just to recap, the truck was running fine, just a little noisy with a bad exhaust. I replaced the exhaust with long-tube headers and dual-exhaust and upon completion, it has a miss. It seems smooth enough at idle, and only becomes really obvious under load, even light load. I had also just cleaned & re-oiled the K&N right before I did the exhaust. I was not excessive on the re-oil.

The only part of the ignition that I touched were the wires, as I had to remove them from the plugs to get the headers in. I swapped in the wires from the Chevelle, which are presumed to be good. No improvement. I pulled the #2 plug and nothing looks 'obviously' wrong to me, but I'm far from an expert plug reader. I guess I should just pull all 8. (All 8 have been replaced in the last 10-15k miles)

I haven't checked for codes, but I also do not have the Service Engine light lit, either.

This is the basic fueling equation in Megasquirt. Note, this is a Speed Density system not utilizing a Mass Airflow sensor (MAF).

Code: Select all

PulseWidth = REQ_FUEL * VolumetricEfficiency * MAP * Enrichments (ie, ColdStartEnrich, AfterStartEnrich, ,AirTempCorrection, O2 sensor..)  + accel + Injector_open_time
While the factory's equation might be slightly different, I think this is good enough for educational purposes. REQ_FUEL is basically an injector constant (sometimes called BPW, I think, in GM-computer-tuning-speak) Paul, the reason your Turbo stuff worked fine without any changes is that the increased boost was handled by the MAP term in the equation, or it was a Mass-Airflow system.

Im thinking the VE, which is basically the engine's ability to breathe, has been improved by the headers. Enough so, that the fuel-trims within the computer do not have enough adjustment to compensate. If I had a way to increase the fuel pressure, that would be a crude way of adding more fuel and letting me know that I was on the right track. Unfortunately, fuel pressure on a GM TBI is not adjustable.

Time to look at the rest of the plugs and do a little more reading, I guess. I have a feeling I'm in for a chip, but that might not be a bad thing.

-Dave
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ttamrettus
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Post by ttamrettus »

That or some oil mist got on the MAF, from I read a while back it's pretty common.
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Basement Paul
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Post by Basement Paul »

If you're going to get a chip, you may want to upgrade your throttle body to the 350 one before you do it.

-BP
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MostMint
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Post by MostMint »

If you think the improved exhaust flow messed it up, why not do something to restrict the exhaust at the tailpipe temporarily to see if it improves.

Oil on the MAF is a good one to check

I assume you checked and rechecked the the firing order - the wires are on the right plugs

Other than that I'd be looking on a truck forum - if it really is going lean due to headers then you are not the first one to have this problem.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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Post by TireSmoker »

Success!

After pulling the plugs out, it was obvious that 6 and 8 were where the problem was. I'm certain I replaced the plugs somewhere after 90 or 95k and it only has 104k now, so not sure why those two were so bad (esp #8 ) I put in a new set of plugs and the chip from tbichips.com also arrived today. I installed it too and my truck runs again.

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It's definitely a bit louder than it was before, but I still don't have tailpipes. It was also raining out by the time I got everything back together and it'll one-wheel-peel in the wet. But it definitely seems to have some additional torque. I never ran the truck down the track in stock form. Maybe I'll just have to catch Fred32v on the street.. :-)

I also put in the order with Mostmint for the new tires. They're out of stock, and it might be a couple weeks before they are in.

-Dave
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Post by TireSmoker »

TireSmoker wrote:So it's been a little over 3 years and I've done absolutely nothing to this truck except change the oil and recently, a set of spark plugs. It's near 100k miles and still runs perfect.
Just had to read back in my own thread here. Those plugs were just about new, barely 4-5k miles. The post was from Nov 2008, so a year ago.
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Post by TireSmoker »

I found a brand new cap and rotor in inventory for the truck. I'll pick up a new set of wires sometime this week, install them all and call the ignition system done for hopefully the next several years.

I got the cracked windshield replaced yesterday. Safelite Glass came out to the house and replaced it. Insurance covered the cost. It's been so long since I had a rearview mirror in the truck, I forgot what it was like.

I met up with GMJohnny over the weekend at the rental store. He put in a call to Paul Carson for me regarding the tailpipes. I'm going to drop the truck off to him this weekend.

I dropped of the new SS rims (steel -- heavy) at Mostmint's this past weekend before the poker game. At some point the back-ordered tires will arrive at Firestone. I found a set of NOS (allegedly) center caps on ebay for $35 shipped. They arrived yesterday.

About the only thing left to address is the monkey under the dash that bangs away when turning the vehicle on or off. Once I get that squared away, it should be as good as new. About the only thing left will be brakes and shocks, and I'm not certain that it needs either of those right now.

-Dave
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Post by TireSmoker »

Took the truck out to Paul Carson on Friday night. As I was heading to Cincy on Saturday, I left it with him over the weekend. Picked it up Monday night. He welded in the existing tailpipes that came with the rest of the exhaust that I bought at Canfield. He fixed up the hangars and re-made the one that VeeDub and I rigged together.

I also had him weld in an O2-sensor bung, so that I could mount my wideband sensor in there. Hey, I haven't gotten much use of it in the Chevelle, might as well try to get some use out of it here! It might be interesting to see what the factory tune looks like, from an A/F ratio perspective.

It's definitely quieter inside with the tailpipes in place. It really sounds much different than before and I'm pretty happy. I'll get a couple pics up.

Once I get the new tires from Mostmint, this season's worth of Trick My Truck will be complete.

The intersection of Auburn & Taylor May doesn't sound that far away. But after dropping it off, getting back home and realizing I left my phone on the seat of the truck, I realized that it's a solid 25 minute drive.

-Dave
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Post by TireSmoker »

The new tires for the truck were finally installed about a week back. I got a killer deal from Mostmint on a set of Firestone Indy 500's, 275-60-15, mounted on a set of chrome 454SS truck wheels. They look great, they give a much nicer ride than the old tires, and they're pretty decent in the snow. All for *well* under $300.

I also replaced the throttle position sensor. I spent more time looking for a dropped torx bit than it took to replace. I was getting a more-frequent Check Engine light which resulted in the transmission shifting issues (because the computer didnt know the throttle position). Very easy fix.

About the only thing I have left to do is fix the banging monkey under the dash. (vent control motor) and everything should be tip-top.

-Dave
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MostMint
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Post by MostMint »

what about the big block? 8)
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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Post by TireSmoker »

In due time! :-)
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TheRookie
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Post by TheRookie »

I think I found the monkey under the dash when I used the truck on Saturday :) (that's a "Family Guy" reference for those who don't know)


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